Combustion and heating apparatus



July 20, 1965 a M. w. s'rou'r COMBUSTION AND HEATING APPARATUS 6 Sheets-Sheet 2 Filed Dec. 11, 1959 mmvron M/A/02 M/ 57"0/7' my 20, 11965 M. w. s-rou'r "3,'l9i5;6-.06

' COMBUSTION AND HEATING APPARATUS Filed 060.. 11 19.5.9 6 isheetssheet :5

INVENTOR.

M INoR W. STovT' ATT y 20, 1955 M. w. s'rou'r 3,195,606

COMBUSTION AND HEATING APPARATUS Filed Dec. 11 1959 6 Sheets-Sheet 4 F316 Q aoa 514 304 FIG 5 ATT July 20, 1965 Filed Dec. 11 1959 M. w. sfou r couaus'n'on mm nm'r'me AIPARATUS 6 Sheets-Sheet 5 July 20, 1965 M. w. STOUT 3,195,606

comaus'non m mums APPARATUS Filed bec. 11, 1959 6 Sheets-Sheet s mmvrm Q Mm/o/e 14 from" United States Patent 3,195,606 CQMBUdTlfiN ANHE HEATING AlPARATUS Minor W. dtout, Webster Groves, M0. (792% Manchester, St. Louis, Mo.) Filed Dec. 11, 195?, Ser. No. $58,963 it Claims. (ill. ass-1) This invention is a continuation-in-part of the invention disclosed in my co-pending application Ser. No. 352,498 which was filed May 1, 1953 for Combustion Apparatus, now Patent No. 3,032,096.

This invention relates to improvements in combustion apparatus. More particularly, this invention relates to improvements in combustion apparatus providing improved combustion of the fuel.

It is therefore an object of the present invention to provide improved combustion apparatus providing improved combustion of the fuel.

The combustion apparatus provided by the present invention fosters prompt and complete burning of the fuel by providing a continuous pilot and by forcing the fuel that is to be burned to pass through the flame of that pilot. As that fuel passes through the pilot flame it is heated and ignited and is caused to burn rapidly. It is therefore an object of the present invention to provide a combustion apparatus wherein a continuous pilot flame is maintained and wherein the fuel that is to be burned is forced to pass through that pilot flame.

The fuel is forced to pass through the pilot flame by disposing the pilot flame so it is coextensive with part of the flame from the fuel nozzle, and by disposing the pilot flame so the fuel from the fuel nozzle must strike and penetrate the pilot flame. As a result, the fuel from the fuel nozzle interacts intimately with the pilot flame to assure prompt heating and ignition of the fuel from the fuel nozzle. It is therefore an object of the present invention to dispose a pilot flame so it is coextensive with part of the flame from the fuel nozzle and so the fuel from the fuel nozzle must strike and penetrate the pilot flame.

Where the fuel from the fuel nozzles is gaseous, that fuel is forced to strike and penetrate the pilot flame by an annular baflle which is mounted at the outlet of the nozzle for fuel. That baffle will force the fuel to move sharply inwardly in conical manner and will produce an unusually short and unusually hot flame. The leading face of that annular baffle is tapered to give that face a frusto-conical configuration, and that configuration helps define :a short cone of fuel which can penetrate and be heated and ignited by the pilot flame. It is therefore an object of the present invention to provide an annular battle for the fuel nozzle of combustion apparatus and to provide the leading face of that baflle with a frusto-conical configuration.

The angle at which the gaseous fuel is caused to move inwardly toward the pilot flame can be additionally sharpened by disposing the battle of the fuel nozzle a short distance forwardly of the outlet end of the next innermost nozzle. T hat disposition effectively establishes a V- shaped, axially-directed cross section for the nozzle; and that cross section forces the fuel to move inwardly toward the pilot flame at a sharp angle. It is therefore an object of the present invention to dispose the baffle for the fuel nozzle a short distance forwardly of the outlet end of the ext innermost nozzle.

The nozzle which is provided for the continuous pilot has a bell month. That configuration of that nozzle keeps the rapidly moving :air and fuel adjacent the pilot nozzle from extinguishing the pilot flame. Consequently, it is possible to use the pilot provided by the present invention with pressurized combustion apparatus. It is therefore an object of the present invention to provide a pilot nozzle with a bell mouth that keeps the pilot flame from being ilhhfillfi Patented July 20, 1965 blown off although air and fuel are moving past the pilot nozzle at a rapid rate.

The combustion apparatus provided by the present invention includes a combustion throat which is external of the fire tubes or water tubes of the boiler or is external of the oil-heating tubes of an oil-cracking still. That combustion throat has a refractory wall in register with the outlet of the combustion head, and the flame from the combustion apparatus will strike that Wall and then rebound back toward further oncoming fuel and the products of combustion. As a result, there is a re-entrant movement of the burning fuel and prodnets of combustion which provides greatly increased turbulence and greatly increased heating and ignition of the oncoming fuel and the products of combustion. As a result, full and complete combustion of large quantities of fuel can be attained in a very short time and in a. very short distance. It is therefore an object of the present invention to provide combustion apparatus which has a combustion throat wherein a wall of refractory material is in register with the outlet of the combustion head and which will cause burning fuel and products of combustion to rebound toward the combustion head.

The refractory wall in register with the combustion head will be heated to incandescence by the burning fuel and products of combustion which engage it. The incandescence of that refractory wall is desirable because it will enhance the heating, ignition and burning of any fuel that strikes that wall.

The combustion head and the refractory wall in register with it define a line that is transverse of the direction which the products of combustion must follow as they transfer their heat to the heat-absorbing surfaces of the boiler or other device to be heated. Furthermore, the combustion head and the refractory wall in register with it are disposed outwardly beyond the sides of the boiler, and hence substantially all of the burning fuel and prodnets of combustion from the combustion head must move transversely of the boiler and must move through a distance greater than the width of the boiler before they can turn and move toward the boil-er. In this way, the burning fuel is given enough time to complete its combustion before it can engage the relatively cool surfaces of the boiler or other device to be heated.

An inner combustion throat is mounted within the combustion throat of the combustion apparatus provided by the present invention, and that inner combustion throat positively confines and guides the burning fuel and products of combustion toward the refractory wall which is in register with the outlet of the combustion head. In d0 ing so, that inner combustion throat keeps the burning fuel and products of combustion from taking a short cut to the relatively cool surfaces to be heated. More spe- .cifically, the inner combustion throat keeps the burning fuel and products of combustion from taking a short cut to the water-backed surfaces of tire tubes or water tubes of a boiler or to the oil-backed tubes of an oil-cracking still. As a result, the inner combustion throat keeps incompletely burned fuel from engaging, and depositing soot or lamp black upon, the relatively cool surfaces to be heated. it is therefore an object of the present invention to provide an inner combustion throat which confines the burning fuel and keeps that fuel from taking a short cut to the relatively cool surfaces to be heated.

The inner combustion throat is heated by the burning fuel and products of combustion passing through it, and itis also heated by the rebounding burning fuel and products of combustion that pass along its exterior. That combustion throat will become incandescent and will foster burning of the fuel passing through it as well as foster burning of any fuel that passes along its exterior. In this 3 way, the inner combustion greatly enhances full combustion of the fueLissuing from the combustion head.

A pluality of ports are provided in a ported member of the inner combustion throat, and those ports are adjacent an orifice plate. The conjoint effect of the ports and of the orifice plate is to cause the burning fuel and products of combustion which issue from the combustion head to inspirate some of the products of combustion that rebound from that wall of the outer combustion throat which is in register with the outlet of the inner combustion throat. The inspira-ted products of combustion that pass through the ports of the ported member of the inner combustion throat mix with, and cause turbulence in, the burning fuel and products of combustion passing through that inner combustion throat. This means that there is a partial recirculation of the products "of combustion and a resultant increase in the rate of ignition and in the rate of burning of the fuel issuing from the combustion head. It is therefore an object of the present invention to provide an orifice plate and adjacent ports in the inner combustion throat of a combustion apparatus.

An explosion window is provided in the wall of the combustion throat that is in register with the combustion head. That explosion window withstand the normal pressures experienced within the combustion apparatus, but is made weak enough to break down when pressures approaching the explosion range are experienced. As a result, that explosion window normally prevents the escape of products of combustion from the combustion apparatus but readily vents those products of combustion before an explosion can build up pressures that will damage the combustion apparatus.

Other and further objects and advantages of the present invention should become apparent from an examina tion of the drawings and accompanying description.

In the drawings and accompanying description several preferred embodiments of the present invention have been shown and described but it is to be understood that the drawings and accompanying description are for the purpose of illustration only and do not limit the invention and thatthe invention will be defined by the appended claims.

In the drawing:

FIG. 1 is a vertically-directed, longitudinal section through one form of combustion head that embodies the principles and teachings of the present invention,

FIG. 2 is a vertically-directed, longitudinal section through another form of combustion head that embodies the principles and teachings of the present invention,

FIG. 3 is a sectional view through the combustion head of FIG. 2, and it is taken along the plane indicated by the line 33 in FIG. 2,

FIG. 4 is anothersectional view through the combustion head of FIG. 2, and it is taken along the plane indicated by the line 44 in FIG. 2,

FIG. 5 is an enlarged sectional view through the combustion head of FIG. 2, indicated by the line 5-5 in FIG. 2,

FIG. 6 'is a partially-sectioned, broken, plan view of one form of combustion apparatus that is made in accordance with the principles and teachings of the present invention,

FIG. 7 is a sectional View throughthe combustion apparatus of FIG. 6, and it is taken along the plane indicated by the line 7-7 in FIG. 6,

FIG. 8 is a sectional view, on a larger scale, through the I combustion apparatus of FIG. 6, and it is taken along the plane indicated by the line 8-8 in FIG. 6,

FIG. 9 is a partially-sectioned, broken, plan view of another form of combustion apparatus that is made in accordance with the principles and teachings of the present invention, and it is takenalong the plane indicated by the line 99 in FIGVIO, and

FIG. 10 is a sectional view through the combustion apis made strong enough to and it is taken along the plane 7 way 40; and the front with the opening. 32 and 'by the line 10I0 in FIG. 9.

Referring to FIG. 1 indetail the numeral 18 denotes a metal cylinder, which is part of one form of the combustion head that is made in accordance with the principles and teachings of the present invention. A flange 20 is provided at the right-hand end of that cylinder, and that flange can be secured to a combustion throat by bolts or other fasteners. An end wall 24 closes the left-hand end of the cylinder 18, and that end wall will be welded to the cylinder 18. A tube 26, which is large enough to accommodate the hand of a human being, is Welded to the cylinder I8; and an opening 27 is provided in the cylinder 18 to permit the interior of the tube 26 to communicate with the interior of the cylinder 18. An annular cap 28 is provided forthe tube 26, and threads on the tube and cap will provide a tight seal between that tube and cap while permitting separation of the cap from that tube. Two annular gaskets 29 are disposed within the cap 28, and they are on opposite sides of a glass pane 34) held in that cap. The pane 39 permits inspection of the interior of the cylinder 18. The tube 2s makes it easy for the operator of the combustion head to thrust his hand through the tube 26 and into the cylinder 18 to make any adjustments that may be necessary. Moreover, the tube 26 and the pane 20 make it possible to visually inspect the operation of the burner.

An opening 32 is provided in the side of the cylinder 18. A suitable scanning device can be placed in register held there by a coupling pipe welded to the exterior of the cylinder 18. One such scanin E. Craig Thomson Patent 2,624,398 which issued January 6, 1953, and another such scanning device is shown in my Patent 2,805,652 which issued September 10, 1957. Either of those scanning devices can be used with the combustion head of the present invention, but neither of those scanning devices forms a part of the present invention.

A metal cylinder 34, which is shorter than the cylinder tending annular flange 36 is formed on that right-hand end of the cylinder 34. This annular flange will preferably welded to the right-hand cylinder 34. The cylinders 18 and 34 will opening in the end wall 24, and the exterior of the cylinder 65 will be Welded to the portions of the wall 24 which define that circular opening. V

A portion of the left-hand end of the cylinder, 18 is cut away to accommodate a passageway 40. The right-hand Wall of the passageway 49, as that from the left-hand end of the'combustion head shown in FIG. 1, is welded to one of the longitudinally-extendin'g edges of cylinder 18 which define the cut-away portion of the left-hand end of that cylinder; and the left-hand wall 45 of that passageway extends upwardly through the cut away portion at the left-hand end of the cylinder 18 and is wall of that passageway is a plate 51 which is welded to the forward-most edge of the edges of cylinder 18 which define the cut-away portion at the left-hand end of that cylinder; The passageway tl will direct fluid into the annular area between the cylinders 18 and 34- and will cause that fluid to rotate.

The cutaway portion at the left-hand end of cylinder 18 and a cut-away portion at the left-hand end of cylinder 34 accommodate a passageway 44, and in FIG. 1 that passageway is disposed rearwardly of the passageway 40. The

left-hand wall of the passageway 44, as that passageway is viewed from the left-hand end of the combustion head shown in FIG. 1, is welded to the other of the longitudinally-extending edges of the cylinder 13 which define the cut-away portion at the left-hand end of that cylinder, but it extends upwardly beyond that other longitudinally-extending edge and is welded to one of the longitudinallyextending edges of cylinder 34 which define the cut-away portion at the left-hand end of that cylinder. The lower part of the right-hand wall of the passageway 44 is the wall 45, and the upper part of that right-hand wall projects upwardly through the cut-away portion at the left-hand end of the cylinder 18 and is welded to the other of the longitudinally-extending edges of cylinder 34 which define the cut-away portion of that cylinder. The passageway 44 will have the end wall 24 as the rear wall thereof, as that passageway is viewed in FIG. 1, and the front wall of that passageway will be the plate 41. The passageway 44 will conduct fluid to the annular space between the cylinders 34 and 66 and will cause that fluid to rotate in a direction opposite to the direction of rotation of the fluid introduced between the cylinders 18 and 34 by the passageway 4h. The wall 45 extends between and isolates the passageways 40 and $4 from each other at a point spaced above the bottom of the passageways 4t} and 44.

The bottoms of the passageways 4d and 44 will be connected by a duct, not shown, to a motor-operated blower, not shown. When the blower is operating, it will force fluid through the passageways 4t} and 44 and cause the fluids to rotate in opposite directions and to issue from the nozzles at the right-hand ends of the cylinders 18, 34 and as in counter-rotating directions, all as shown and de scribed in said co-pending application. The annular space between the cylinder 18 and the cylinder 3% is larger than the annular space between the cylinder 34 and the cylinder 66, and the passageway it) is larger than the passageway 44.

Two channels 56 are mounted in the passageway 40, and the flanges of those channels support an adjustable valve 52 in the form of an L-shaped damper. Similarly, two channels, not shown, are mounted on the side walls of the passageway 44, and the flanges or" those channels support an adjustable valve, not shown, in the form of an L-shaped damper. The free ends of the adjustable valves are held in adjusted position relative to plate 41, which constitutes the front walls of passageways 4d and 44, by nuts which are mounted on threaded studs. The nuts 56 and 57 for the valve 52 are adjustably mounted on a threaded stud 54, as shown in FIG. 1. The nuts and threaded studs for the adjustable valve for the passageway 4d are behind and are obscured by the nuts 56 and 57 and by the threaded stud 54. Those threaded studs are welded to the end wall 2 6, and adjustment of the positions of the nuts on those studs will shift the adjustable valves transversely of passageways 44 and 4t) and thereby determine the sizes of the openings defined by the free ends of the valves and the adjacent wall 41 of the passageways 44 and 4d; and the sizes of those openings will determine how much of the air supplied to the common entrance of passageways 4 and 4% will pass through each of those passageways. Proper setting of the nuts on those studs will provide the desired division between the air passing to the passageways 44 and 42) and thus to the nozzles defined by the cylinders 34 and 6e and by the cylinders 18 and 34. A pipe 58 extends through the end wall 24 of the combustion head and has its other end welded to the forward wall of the passageway 44-. A plurality of openings, not shown, are drilled in the upper side of the pipe 58 and those holes serve as jets for combustible fluid. This fluid may be natural gas, water gas, butane, propane or the like. The left-hand end of the pipe 58 will be connected to a pipe, not shown, that extends from a manually-adjustable valve. The manually-adjustable valve in turn will be connected to an electrically-operated valve that is connected by a pipe to a suitable source of combustible fluid. The manually-adjustable valve can be set to determine the rate of flow of gas into the pipe 58, and the electrically-controlled valve will determine when gas will flow to the pipe 58. The above-described combustion head is denoted generally by the numeral 146.

The cylinder 66 has the left-hand end thereof .closed by an end wall '76, and it has a flange 68 of annular form welded to the right-hand end thereof. The cylinder 66 encircles a cylinder 72 which is also secured to the end wall 7%. The right-hand end of the cylinder 72 has the exterior thereof spaced from the annular flange 68 on cylinder as to define a nozzle of predetermined area. The interior of the right-hand end of the cylinder 72 has an annular recess 7d formed therein and that recess defines a nozzle of predetermined area. The cylinder 66 is cut away at points, not shown, and the cylinder 72 is cut away at points, not shown, to accommodate the ends of two passageways which are shown in the above-identified co-pending application. One of those passageways introduces air from a second blower into the cylinder 72 at one side thereof and causes that air to move circumterentially through that cylinder. The other passageway introduces a mixture of air and combustible fluid into the cylinder at and causes that air and combustible fluid to move circumferentially of that cylinder. The directions of rotation of the air in cylinder '72 and of the air and combustible fluid in cylinder 66 are opposite to each other, thus providing a counter rotation of the fluids in the two cylinders.

A smooth walled pipe 1% extends through the end wall "ill and is welded to that wall. An annular groove 102 is formed in the exterior of that pipe adjacent the right-hand end thereof and that annular groove defines a radiallyextending projection 194 at the right-hand end of that pipe. A number of circumferentially spaced openings 1% extend through from the smooth walled interior of the pipe liltl to the annular recess or groove 102 in the exterior of pipe 1%. A larger diameter tube 168 is telescoped over the right'hand end of the tube 1% and is secured to that tube. The interior of that larger diameter tube 108 is cut away to a pro-determined dimension. This cut-away portion coacts with the annular groove 102 to define an annular passageway and coacts with the radially-extending projection 104 to define an annular nozzle of predetermined area. The right-hand end of the tube ltlfl extends axially beyond the right-hand end of the tube 1%. Moreover, the tube 168 extends radially outwardly beyond the outer diameter of the pipe liltl. A pipe 11d of still larger diameter is telescoped over the exterior of the pipe 198 and is welded to that pipe. This pipe extends both axially and radially beyond the tube 138. The radially extending projection 104 on the pipe Mid and the cut-away portion of the pipe 1% define an annular nozzle for a pilot. The tube 110 serves to protect that pilot by deflecting air outwardly from that pilot and by shielding that pilot from that air.

The left-hand end or" the pipe tilt) extends into a fortyflve degree junction 112. A nipple 114, which is suitably connected to a source of combustible gas, extends downwardly at forty-five degrees from the junction 112 and a manually-adjustable valve and an electrically-responsive valve will be serially-connected to the nipple 114. Adjustment of the manually-operable valve will control the amount of combustible fluid that enters the pipe Tilt) and the electrically-responsive valve will determine when that combustible fluid enters the pipe 100. The electricallyresponsive valve will be controlled by a circuit which includes the spark-forming electrodes 128.

A blower 116 is connected to the end of the pipe 1% by an intervening coupling pipe 118, and it will force air and combustible fluid through the pipe 1% and out the right-hand end of that pipe. A small portion of the admixed air and combustible fluid will pass through the openings 1% into the annular passage defined by the groove till and the cut away interior of the pipe 1%. This pre-mixed combustible fluid and air will then issue through the nozzle of annular form defined by the radially extending projections 1943 and the cut away interior of the pipe 1%. The rest of the pre-mixed air and combustible fluid will issue in a stream from the right-hand end of the pipe 1%. When the pilotis lighted, it will have an annular flame at the annular orifice defined by the projection 104 on pipe Tilt) andby the cut away portion of the pipe 198, and it will also have a flame extending outwardly from the right-hand end of the pipe 109. That flame will preferably be from one to two feet or longer in length and it will serve to ignite the combustible fluid issuing from the cylinder 66 or the cylinder 34.

A nozzle 1243 for a non-gaseous dered coal or the like, is disposed Within the pipe 1%.

This nozzle will provide a counterclockwise rotation of the non-gaseous fluid fuel issuing therefrom, as that rotation is determined from the left-hand end of the combustion head of FIG. 1. The nozzle 120 is supported by the pipe 122 which extends through the pipe 1% to a point exteriorly of the end plate 76 and then passes through the wall of the pipe 1%. 'An electrically-operated valve 123 is connected to the pipe 122, and that valve selectively prevents or permits non-gaseous. fuel to flow to the nozzle 120. A weld will provide an air-tight joint between the pipe 122 and the pipe 190, and that weld will hold the pipe 122 and the nozzle 12f) concentric with the pipe 1%. The fluid fuel from the nozzle 12% will pass through the pilot flame and will pass through the flame supported by the combustible fluid from cylinder 66 and the air from cylinder 72. That latter flame will preferably be from three to four feet or longer in length and will subject the fluid fuel from nozzle 120 to rapid and high heating. Moreover, that flame will cause turbulence and will break up the fluid fuel from the nozzle 120 and intimately admix it with the air from the cylinder 72 and from the cylinder id to provide prompt and complete burning of that fuel.

Insulators 124 extend through the wall of the cylinder 18 and are sealed to that wall by suitable seals 126. The insulators 124 carry and support the electrodes 12%; which are connected to leads'130. The electrodes 128 are spaced apart to provide a gap, and when a spark bridges that gap that spark will ignite the combustible fluid in the combustible head, The wires 130will be connected to a suitable source of high voltage electricity to assure positive bridging'of the gap between the electrodes 128.

In using the combustion apparatus provided by the present invention, the flange 20 of the combustion head will be secured to a combustion throat as by bolts or the like. To initiate the operation of the combustion apparatus, a spark is caused to bridge the gap between the spaced electrodes 128 and the electrically-controlled valve for the pilot opens and permits combustible fluid to enter the pipe ltltt. Simultaneously, the blower 116 will start and will force the pre-mixed air and combustible fluid outwardly from the pipe 1% and outwardly from the annular nozzle defined by the radially-extending projection 194 and the cut-away section of the pipe me. This mixture of air and combustible fluid will be ignited by the spark that bridges the gap between the spaced electrodes 128. The manually-operable valve between the electrically-operable valve and the nipple 114 will then be adjusted to provide the desired air-combustible fluid ratio to attain full burning of that fluid to carbon dioxide with a minimum of excess air. An adjustable valve in the form of a damper 1119 is provided between the blower 116 and the pipe 1% to control the volume of air delivfuel, such as oil or powof combustible fluid and air. That valve will'then be ad justed to assure full conversion of that combustible fluid to carbon dioxide with a minimum of excess air. The

combustible fluid and air issuing from the cylinders 66 and "72 will establish a low fire which will have a length of from three to four feet or longer; the length being determined by the settings of the dampers in the passage ways leading to those cylinders. Once the low fire has been regulated, it can be extinguished by stopping the blower motor.

Thereafter, the blower connected to the passageways 4t) and 44 can be energized and the electrically-responsive valve will be opened. This will permit combustible fluid to enter the pipe 53 and issue from the holes in that pipe. The air in passageway 44 will carry that com bustible fluid to the right-hand end of the cylinder 34.

This mixture of air and combustible fluid will be ignited by the pilot and will establish a high fire extending for from six to eightfeet or longer through the combustion head and into the combustion throat to which the flange 29 is secured. The valve connected to the pipe 58 can be adjusted to determine the desired volume of combustible fluid, and the damper 52; and the damper for the passageway 4-4 can be adjusted to effect the desired distribution of air between the passageways 4t? and 44- and to attain full combustion of the fuel without too much excess air. Once the proper adjustment of those dampers and of that valve have been attained, the blower to the passageways 45B and 44 can be shut off.

The present invention provides three regulated volumes of combustible fluid and three regulated volumes of supporting air therefor. Moreover, the present invention makes it possible to individually divide the supporting air for the high fire and low fire. In this way it is possible to attain precise control of the burning of the combustible fluid at full capacity and intermediate capacity as well as when the pilot alone is operated. The overall thermodynamic efiiciency can be set and maintained at very high levels. a I

In operation, the pilot is ignited and then operates continuously. The low fire will be controlled, preferably by a steam pressure control switch of usual design and operation, and will cycle according to the demands of the boiler or furnace. When the low fires demand it, the blower which supplies air to the pipes 66 and 72 will start, and air and combustible fluid will be caused to issue from the burner adjacent the pilot flame. The air will carry the combustible fluid through the combustion head and into the combustion throat and that air and combustible fluid will burn vigorously and thoroughly. The combustible fluid in the low fire is ignitedby the pilot and it is rotating in a counterclockwise direction While the supporting air therefor is rotating in a clockwise direction. The interaction of the air and combustible fluid shreads the customary raw gas cone of aldehydes and alcohols and carbon monoxide and provides a homonegenous flame which burns quickly and at high temperature. The low fire flame will be confined closely by the combustion throat and that throat will force the air and combustible fluid and products of combustion to intermingle thoroughly and attain full and immediate burning of the combustible fluid to carbon dioxide. If the demand on the boiler or furnace is low, the low fire will be able to satisfy it and will then be cut off by the steam pressure control or other control mechanisms. If the demand is too great for the low fire, the blower connected to the ered to the pipe 1%. This damper is set so that pilot is I between one and two feet or longer in length.

Once the pilot has been adjusted, the blower which supplies air to the nozzles defined by the cylinders 66 and 72 and by the cylinders 72 and 100 will be started. The manually-adjustable valve that supplies the combustible fluid which issues from the nozzle defined by the pipes 66 and 72 Will be adjusted to provide the required mixture passageways 4t? and 44 will be energized and will move air and combustible fluid into the nozzles defined by the pipes 18 and 34 and pipes 34 and 66. The air issuing from the cylinder 18 and the combustible fluid and premixed air issuingfrom the cylinder 34 will be ignited by the low fire and will promptly burn. The combustible fluid issuing from the cylinder 34 will be rotating in a direction opposite'to that of the combustible fluid issuing from the cylinder 66, and'theair issuing from the cylinder Q 18 will be rotating in a direction opposite to that of the air issuing from the cylinder 72. Moreover, the fluids issuing from the cylinders 18, 34, 66 and 72 will alternate in direction. The overall effect is a complete shredding and breaking up of the raw fuel mantles and the partially burned fuel mantles experienced with most burners. A completely homogeneous and wildly turbulent flame results which assures full and complete combustion to car bon dioxide in a very short length. As the flame passes from the combustion head and into the combustion throat it is held and confined to a very small volume and is forced to thoroughly intermix its component parts and thus assure full combustion.

The nozzle 121) and the pipe 122 will be kept cool both by the passage of the air from the blower 116 to the pipe 191) and by the flow of air through the cylinder 72 from the passageway connected to that cylinder. As a result, the nozzle 120 will remain relatively cool.

If the combustion fluid available for the high fire is on an interruptable basis, and if the outside temperature becomes low enough to cause interruption of the combustible fluid for the high fire, the valve, not shown, which controls the flow of fluid fuel through the pipe 122 and the nozzle 12!), will open. This will cause the oil or powdered coal to pass through the pilot and through the low fire flames and be heated and ignited by those flames. The nozzle 120 is of usual design and construction and will cause the fluid fuel to rotate in a counterclockwise direction as that nozzle is viewed from the left-hand end of the combustion head of FIG 1. This will be opposite to the direction of flow of air in cylinder 66 and will cause countercurrent rotation. The fuel from the nozzle 120 will unite with the fuel of the pilot and of the low fire to provide a thoroughly homogeneous flame of short length and high intensity. The air for the fuel issuing from the nozzle 120 will be supplied by the cylinder 13 and adjacent cylinders. The fuel from the nozzle 120 will operate on a cycle basis depending upon the demand of the boiler or other heating device, in the same way that the fuel from the pipe 58 operates on a cycle basis. Preferably the low fire will operate before the high fire or the non-gaseous fuel fire operates and will continue beyond the time when the high fire or the non-gaseous fuel fire cuts off. While fuel from the nozzle 120 is being burned, the cylinders 13 and 72 are kept cool by the air flowing through them. In this way, the present invention protects the inactive nozzles from the effect of the flame in the combustion hea The present invention also protects the adjusting devices from heat by placing them at a distance from the flame. Thus, the adjustable dampers are in the cool region of the combustion head and the valves for the combustible fluid and for the non-gaseous fluid fuel are in cool areas external of the combustion head.

The present invention can utilize combustible fluids under low pressure because the air flowing past the openings in the pipes for the combustible fluid and flowing past the nipple 114- will inspirate the combustible fluid. For example, the combustible fluid for the pilot in a one hundred horsepower boiler set up can be as low as three quarters of an inch water column and still provide a pilot of from one to two feet or longer in length. Similarly, the combustible fluid for the low fire and high fire may have a pressure of as little as one inch water column and still provide flames of approximately four feet and approximately eight feet in length respectively for that boiler set up. Thls is very desirable because it enables full pressure regulation of the combustible fluid by commercially available pressure regulators between the source of supply of the combustible fluid and the electrically-responsive valves which control the flow of combustible fluid to the pilot, low fire and high fire.

Referring to FIG. 2, the numeral 156 denotes a tube or pipe that is comparable to pipe 66 of FIG. 1. Disposed Within the pipe is a pipe 152 that is generally comparable to the pipe 72 of FIG. 1. However, the left-hand end of the pipe 150 is closed by an annular plate 154 and the left-hand end of the pipe 152 is ciosed by a plate 196. The annular plate 154 is welded to the left-hand end of the pipe 151) and to a portion of the pipe 152 adjacent its left-hand end. An annular flange 158 is provided at the left-hand end of the pipe 152, and that flange is secured to the plate 196 by bolt and nut combinations 1%.

An annular batfle 156 is secured to the right-hand end of the pipe 150, and that baflle has the leading face thereof cut-away to have a frusto-conical configuration. The baflie 156 is disposed to the right of a plane which is defined by the right-hand end of the pipe 152.

A pipe 161?, which is generally comparable to the pipe 34 of FIG. 1, encircles the right-hand ends of the pipes 156 and 152. A pipe 162, which is generally comparable to the pipe 18 of FIG. 1, encircles the pipe 161). A plate 164 has a central opening 165 to accommodate the left-hand end of pipe 150, and that plate closes the left-hand ends of the pipes 161 and 162. An annular baflie 166 is provided at the right-hand end of the pipe 160, and that baffle is disposed to the right of a plane Which is defined by the outer face of the annular baflle 156. The baffle 166 has the leading face thereof cut-away to have a frusto-triangular configuration.

The numeral 168 denotes a baflie which is positioned within the pipe 162, and that baflle is disposed to the right of a plane defined by the outer face of the baffle 166. The baflle 168 has the leading face thereof cutaway to have a frusto-conical configuration. A series of brackets 170, one of which is shown, is secured to the interior of the pipe 162, as by bolts or screws, not shown. Nut and bolt combinations 172 secure the baflie 16% to those brackets. The brackets 170 and the bafiie 168 can be shifted somewhat along the length of the pipe 162; and such shifting will be relied upon in the event a different fuel is to be used or a different heating capacity is to be provided. The shifting of the brackets 170 and of the baflle 168 along the length of the pipe 162 will change the angle at which the fluid passing through the pipe 162 will start moving inwardly toward the axis of the pipes 152, 150, 160 and 162.

The angles at which the fluids issuing from the pipes 168 and 150 will start moving inwardly toward the axis of the pipes 152, 150, 160 and 162 can be changed by changing the apex angles of the frusto-conical configurations for the leading faces of the baffles 166 and 156, respectively. Also, the angles at which the fluids issuing from the pipes 160 and 150 will start moving inwardly toward the axis of the pipes 152, 150, 161) and 162 can be changed by changing the distances which the battles 166 and 156 are set forwardly of the baflle 156 and of the outlet end of the pipe 152, respectively. The fact that the angles at which the fluids issuing from the pipe 162 and from the pipes 160 and 151 will start moving inwardly toward the axis of the pipes 152, 151i, 161) and 162 can be changed enables the present invention to assure full and highly efficient combustion of many different fuels and at different heating capacities.

In FIG. 1, the baffles 36 and 68 at the outlet ends of the pipes 34 and 66, respectively, materially shorten the low fire flame and the high fire flame. In FIG. 2, the baffles 156 and 166 at the outlet ends of the pipes 150 and 160, respectively, shorten the low fire flame and the high fire flame to an even greater extent, because of the frusto-conical configurations at the leading faces of those baflles and because of the advancement of those baffles. The baflie 168 and its frusto-conical leading face and its advancement act to shorten the high fire flame even further. The overall result is that the combustion head of FIG. 2 can burn the same 272 in FIG. 2.

aneseee amount of fuel in a shorter distance than can the combustion head of FIG. 1, or it can burn more fuel in the same distance as can the combustion head of FIG. 1.

The numeral 174 denotes the left-hand wall of a pas sageway 173, as that passageway is viewed in FIG. 3, and that wall extends through a cut-away portion at the rear of the pipe 162 and extends to a cut-awayportion at the rear of the pipe 160. The wall 174 is welded to one of the longitudinally-extending edges which define the cut-away portion at the rear of the pipe 162, and it is also welded to one of the longitudinally-extending edges which define the cut-away portion at the rear of the pipe 160. A partition 175 'is spaced a short distance to the right of the wall 174, and'that partition extends through the cut-away portion at the rear of the pipe 162 and extends to the other of the longitudinally-extending edges which define the cut-away portion at the rear of the pipe 1&1 The upper end of the partition 175 will be suitably welded to that other longitudinally-extending edge at the rear of the pipe 160. The plate 164 constitutes the rear wall of the passageway 173, and a plate 179 constitutes the front wall of that passageway. The plate 179 extends upwardly through the cut-away portions at the rear of the pipes 162 and 160 and is welded to those edges of those pipes which define the forward limits of those cut-away portions. The left-hand portion of the top edge of the plate 179'is cut-away to conform to the curvature of the pipe 160. a

The passageway 173 will conduct fluid to the annular space between the pipes 160 and 150, and that fluid will rotate in the clockwise direction asthose pipes are viewed in FIG. 3. That fluid will follow a helical path as it moves along through the annular space between the pipes 160 and 151 and that fluid will continue to move circumferentially as it moves beyond the baffle 166. As that fluid moves beyond the baifle 166, that fluid will be directed conically inwardly toward the axis of the pipes 152, 150, 161) and 162; and that fluid will start to follow the path indicated by the dotted lines The partition 175 also defines one wall of a passage of the passageway 173 in FIG. 3. A plate 177 defines the opposite side of the passageway 171, and that plate extends to, and is welded to, the other of the longitudinally-extending edges which define the cut-away portion at the rear of the pipe 162. The plate 164 constitutes the rear wall of the passageway 171, and the plate 175 constitutes the front wall of that passageway. The right-hand portion of the top edge of the plate 179 is cut-away to conform to the curvature of the pipe 162.

A curved plate 115% is secured to the partition 175; and that plate extends upwardly and to the right from that partition, as shown by FIG. 3. The upper end of that curved plate is welded to the pipe 161), and it helps start some of the fluid in the passageway 171 moving to the right. The fluid in the passageway 171 will move into the annular space defined by the pipes 162 and 160, and that fluid will rotate in the counter clock-' wise direction. That fluid will follow a helical path as it moves along through the annular space between the pipes 162 and 160, and that fluid will continue to move circumferentially as it moves beyond the baffle 168*. As that fluid moves beyond the baifie 168, that fluid will be directed conically inwardly toward the axis of the pipes. 152, 150, 160 and 162; and that fluid will start to follow the path indicated by the dotted lines 274 in FIG. 2. I

' The numeral 176 denotes guides which are secured to the inner face of wall 174 and to the left-hand face of the partition 175. Those guides confine and guide an L-shaped damper or valve 178. The vertically directed portion of the damper 178 has an opening through it, and

. 12 that opening telescopes over a't-hrea'ded stud 1859 which is welded to the outer face of the plate 164. Nuts 182 and 184 are'threaded onto that stud and abut the opposite faces of the vertically-directed portion of the damper 178; and rotation of those nuts relative to that stud determines the position of the forward edge of that damper relative tothe forward with 179 of the passageway 173.

Guides 176 at the inner face of the wall 177 and at the righthand face of the partition 175 confine and guide an L-shaped damper or valve 183. The vertically-directed portion of the damper 133 has an opening in it, and that opening telescopes over a threaded stud 185, which is welded to the outer face of the plate 164. A nut 137, comparable to the nut 184, and a nut, not shown, which is comparable to the nut 182 are threaded onto the stud 185 and abut the opposite faces of the vertically-directed portion of the damper 183. Rotation of the two nuts relative to the stud 135 will adjust the position of the damper 183 and will determine the distance between the forward edge of that damper and the wall 17% of the passageway 171.

An inclined baffle plate 186' is secured to the wall 174 and to the partition 175, and an oppositely-inclined baflie plate 188 is also secured to the wall 174 and to the partition 175. Those bafile plates confine and restrict air passing upwardly through the passageway 173 and provide a venturi-like action. As a result, when air passes upwardly between the baflie plates 186 and 188, a reduced pressure is created adjacent the upper ends of those baflles. That reduced pressure will help draw combustible V fluid from openings, not shown, in the pipe 1%; and that reduced pressure will also foster full mixing of that combustibie fluid with that air.

Referring to FIG. 4, the numeral 139 denotes a wall which extends to one of two longitudinally-extending edges which define a cut-away portion at the rear of the pipe 150. The numeral 1H denotes a partition that extends through that cut-away portion at the'rear of the pipe 150, and that partition'is welded to the exterior of the pipe 152. The partition 191 and the wall 189 define two sides of a passageway 1&1, and the plate 164 constitutes the front of that passageway. A flat plate, not shown, constitutes the rear Wall of the passageway 1&1; and that passageway will conduct fluid to the annular space between the pipes 151) and152. I That fluid will rotate in the counter clockwise direction as it passes into the annular space between the pipes 151? and 152, and that fluid will follow a helical path as it moves along through that annular space. That fluid will continue to rotate as it passes beyond the battle 15 5, but that baffie will cause that fluid to move comically inwardly toward'the axis of the pipes and 152; and that fluid will start moving inwardly along the path defined by the dotted lines 270 in FIG. 2.

An L-shaped damper or valve 193 is mounted within the passageway 181, and that damper is suitably confined and guided by guides 1%". A threaded stud and a pair of nuts, not shown, will be provided to adjust the distance between the forward-edge of t re damper 193 and the plate 154-. The damper 15 3 is generally comparable to the damper 178 of FIGS. 2 and 3. r

A baffle plate 197 and a baffle plate 199 are secured to the plate 164 and to the rear wall of the passageway 1S1. Those'bafles incline toward each other and they will respond to the passage of air therebetween to provide a reduced pressure'ad 'acent their outlet ends. That reduced pressure helps aspirate combustible fluid which issues from openings, not shown, in the pipe 291. That aspirating action facilitates full rrixing of'that'cornbustible fluid with'that air. g

A wall 2113 coasts with the partition 191 to define a second passageway 26%. That wall is welded to the other of the two longitudinally-extending edges that define the cut-away portion at the rear of the pipe 159, but that wall also extends beyond that edge and is welded to one of the two longitudinally-extending edges that define the cutaway portion at the rear of the pipe 152. A curved plate 211 is connected to the partition 191, and it extends downwardly and to the left from that partition. The left-hand end of that curved plate is welded to the other of the longitudinally-extending edges t at define the cut-away portion at the rear of the pipe 152. The passageway 2G9 will conduct air to the annular space between the pipes 150 and 226, and that air will rotate in the clockwise direction.

An L-shaped damper or valve 2435 is mounted in the passageway 209, and that damper is suitably confined and guided by guides 26?. A threaded stud and nuts, not shown, will suitably position the damper 295 relative to the plate 164. The damper 265 is generally comparable to the damper 183 of FIG. 3.

A blower, not shown, will be connected to the inlet ends of the passageways 171 and 1'73 of FIG. 3, and angles 192 are provided to facilitate the connection of that blower to those inlet ends. Screws 1% extend through openings in those angles and seat in threaded openings in the plates 164 and 179. Similarly, a blower, not shown, will be connected to the inlet ends of the passages 181 and 2%9 of FIG. 4. The dampers 1'78 and 183 can be adjusted to control the division of the air entering the passageways 173 and 171, respectively; and the dampers 193 and 265 can be adjusted to control the division of the air entering the passageways 181 and 2119.

The air which enters the passageway 171 provides the oxygen for the high fire flame, and the air which enters the passageway 173 mixes with combustible fuel from the pipe 19% to provide the pre-mixed fuel and air for the high fire fiame. The air which enters the passageway 181 mixes with the combustible fluid from the pipe 291 to provide the pro-mixed fuel and air for the low fire flame, and the air which enters the passageway 2119 provides the oxygen for the low fire flame. The blowers for the low fire flame and for the high fire flame will be suitably controlled so they operate only when their respective flames are required.

The numeral 2&0 denotes an internallydhreaded coupling which is telescoped through, and is welded to, an opening in the middle of the plate 195. A length of pipe 292 is threaded into and is held by the left-hand end of the coupling 2%, and a T-junction 204 is supported by the left-hand end of the pipe 2%2. A nipple 2% is connected to the downwardly directed port of the T-junction 204, and that nipple supports a second T-junction 2&8. A reducer 211) is mounted in the right-hand port of the T-junction 298, and a second reducer 212 is mounted within the reducer 218. A nipple 214 is seated in the reducer 212 and that nipple supports an electrically-controlled valve 215. A gas pipe 218 is connected to the inlet of the valve 216.

A nipple 222. is seated in the bottom port of the T- junction 2G8, and a cone 229 has its lower end disposed within the nipple 222. As a result, the nipple 222 holds the cone so it is coaxial with the vertically-directed passage through that T-junction. The exterior of the cone 220 is in register with the nipple 214 that coacts with the reducers 210 and 212 to connect the electrically-operated valve 216 to the T-junction 2G8. As a result, air flowing upwardly through the cone 221 will have to pass through the reduced upper end of that cone before it can mix with the gas supplied by the nipple 214. The conical member 221) provides a venturi-like action that creates a reduced pressure adjacent its upper end; and that reduced pressure is helpful in aspirating the gas from the nipple 214 and in efiecting full mixing of the air and gas.

A blower 224 is suitably connected to the nipple 222, and that blower provides the air which passes upwardly through the conical member 224 That air will continue upwardly through the T-junction 2G8 and into the T- junction 204; and then that air will turn to the right and pass through the pipe 2%32 to the coupling 2%.

A section of pipe 226 is seated in the right-hand end of the internally threaded coupling 2%, and the right- 1% hand end of that pipe supports an internally threaded coupling 228. A short length of pipe 230 is seated in the right-hand end of the coupling 228. A11 axially-extending and circumferentially-extending groove 232 is machined in the exterior of the pipe 23% adjacent the right-hand end ofthat pipe, and that groove helps define a radially-extending flange 233 at the extreme right-hand end of that pipe. Openings 235 are provided in the wall of the pipe 23% adjacent the left-hand end of the groove or recess 232; and those openings incline outwardly and to the right in FIG. 2.

A pipe 234 has part of its interior cut away, as a 236; and that pipe is telescoped onto the pipe 230. The cutaway portion 236 of the pipe 234 coacts with the groove or recess 232 of the pipe 231) to provide an annular chamber. The openings 235 place that annular chamber in communioaion with the interior of the pipe 230. The radially-extending flange 233 at the right-hand end of the recess 232 coacts with the cut-away portion 236 of the pipe 234 to define an annular nozzle of the required cross section. The right-hand end of the pipe 234 is belled outwardly, as at 233, to provide an outwardly-direction portion at the exterior of the pipe 234-.

The normal outer diameter of the pipe 230 is just slightly smaller than the normal inner diameter of the pipe 234. As a result, the pipe 234 will hold itself in coaxial relation with the pipe 239 but can be shifted axially relative to the pipe 230. A suitable set screw, not shown, will be provided to hold the pipe 234 against accidental shifting relative to the pipe 23%; but that set screw can be loosened to permit adjustment of the axial positions of the pipes 230 and 23 1-. Such adjustment will make it -a simple matter to make certain that the annular pilot flame will neither flashback nor blow off.

The numeral 2% denotes a pipe which is radially directed of the pipes 161 and 162, and which is disposed within alincd openings in those pipes. The lower end of the pipe 240 is threaded, and that lower end is seated within the internally-threaded upper end of a short sleeve 24-2. That sleeve is disposed within openings adjacent the right-hand ends of the pipes 159 and 152. Welds suitably secure the sleeve 242 in position relative to the pipes and 152, and once those welds have been formed, the lower end of the pipe 24! can be passed through the alined openings in the pipes 162 and 160 and seated in the upper end of the sleeve 242. Welds can then be formed between the pipe 241 and the openings in the pipes 169 and 162.

A glow plug 244 is suitably welded to the pipe 234 ad acent an opening in the top of that pipe, and that glow plug can ignite pro-mixed air and combustible fiuid issuing from the annular chamber defined by the recess 232 and the cut-away portion 236. The glow plug 244 is grounded to the pipe 234 by the weld which secures that plug to that pipe, and an electrode 246 extends upwardly from the glow plug to a suitable source of electricity. The glow plug 244 is adjacent the outlet end of the pipe 239 and thus will assure prompt ignition of the annular and main pilot flames, but that plug is spaced inwardly of the outlet end of pipe 234 and is thus protected.

The pipe 240 is large in diameter compared to the diameter of the electrode 246 and to the diameter of the glow plug 244-; and that pipe will isolate the electrode 246 from ground.

The pipe 240 will be cooled by the fluids which engage it as they pass through the annular spaces defined by pipes 162 and 160, by pipes 150 and 150, and by pipes 150 and 152. The pipe 240 will also be cooled by air that passes through the annular space defined by the pipes 150 and 152 and then turns and passes outwardly through the pipe 240 to the exterior of the combustion head. Because it is cool, the pipe 240 will prevent overheating of the glow plug 244 and of its electrode 246.

An important function of the pipe 2 10 is the isolating caused to open and the glow plug 244 is protected from the 15 of the electrode 246 from the pipes 162, 160, 15% and 152 while also isolating from each other the fluids in the annular spaces defined by the pipes 162 and 161 by the pipes 160 and 150,. and 'by the pipes 150 and 152. If the electrode 246 were merely mounted in alined openings adjacent the ends of the pipes 162, 169, 151 and 152, the fluids in the various annular spaces could intermix in advance of the time they issued from the outlet ends of those annular spaces; and any such advance intermixing would be very objectionable. Any and all such advance mixing is positively prevented by the pipe 249.

The left-hand port of the T-junction 204, at the left side of FIG. 2, is closed by a plug 248. That plug has two horizontally-directed openings through it; and a pipe 250 is disposed in one of those openings while a pipe 256 a is disposed in the other of those openings. Suitable Welds will maintain air-tight seals between the plug 248 and the pipes 250 and 256.

An L 252 is threaded onto the left-hand end of the pipe 250, and that L supports a nipple which extends to a solenoid valve 254. An L 258 is threaded onto the lefthand end of the pipe 256; and that L supports a nipple and a solenoid valve 260. Suitable oil-supplying lines will extend to the solenoid valves 254 and 260.

The right-hand end of the pipeZSt) supports an oil spray nozzle 262; and that nozzle is selected so the spray of oil which it produces will not impinge upon either the right-hand end of the pipe 230 or upon the right-hand end of the pipe 234. The right-hand end of the pipe 256 supports a dual oil spray nozzle 264; and that dual spray nozzle isselected so the sprays of oil which it produces will not impinge upon the right-hand end of the pipe'230 or upon the right-hand end of the pipe 234.

The pipe 230 must have a substantial inner diameter to accommodate the oil spray nozzles 262 and 264; and the inner diameter of that pipe is so large that its internal cross section must be reduced to prevent flash backs. The presentinvention provides the requisite reduction in cross section for the pipe 239 by disposing axially-directed blocks 27 within that pipe adjacent the outlet end of that pipe. One of those blocks is shown in FIG. 2, and all three of those blocks are shown in FIG. 5.

To operate the combustion head of FIG. 2, the blower 224 is actuated and caused to move air through the cone 220, through T-junctions 208 and 204, and then through pipes 292, 222 and 23d. Thereafter the valve 216 will be will be energized. The gas from the valve 216 will be aspirated into, and Will be mixed with the air issuing from the top of the cone 220; and the resulting pre-mixed gas and air will pass to the pipe 230. Part of that pre-mixed gas and air will pass outwardly and forwardly through the openings 235 into the annular chamber defined by the recess 232 and the cut-away portion 236, while the rest of that premixed air and gas will issue from the right-hand end of the pipe 230. The glow plug 244 will ignite the pre-mixedair and gas that issues from the annular chamber defined by the recess 232 and the cut-away portion 236, and that pre-mixed gas and air will establish and maintain an annular pilot flame. The glow plug 244 and the annular pilot flame will ignite the main pilot flame, and that main pilot flame will be cylindrical in configuration and will project from one to three feet beyond the outlet end of the pipe 234.

The annular flame adjacent the annular flange 233 is .mingling of the main pilot flame,

tion; and it provides full assurance that even if the main pilot flame Were somehow to be accidentally blown out, that main pilot flame would be re-ignited immediately. In this way, the annular pilot flame and the main pilot flame coact to keep combustible fluid from accumulating within the combustion head and subsequently causing an explosion. 7

Once the main pilot flame has been established, the glow 'plug 244 can be de-energized. A suitable monitoring device, of standard design, can be used to monitor the main pilot flame; and that monitoring device will be suitably interconnected with the electrically-responsive valve 216. If the main pilot flame should somehow become extinguished, the valve 216 will close and will remain closed until that main pilot flame is again re-established.

The blower that supplies air to the passageways 181 and 209 will then be actuated; and, in the event gas is to be used as the 'fuel, the valve connected to the pipe 291 will be opened. Pre-mixed air and fuel will issue from the annular passage between the pipes 150 and 152, and supporting air will issue from the annular passage between pipes 152 and 230. That premixed gas and air and that supporting air will establish a low fire for the combustion head. The pre-mixed fuel and air will start inwardly along the path indicated by the dotted lines 270; and the inclination of that path and the velocity of that pre-mixed fuel and .air are such that the pre-mixed fuel and air penetrate the main pilot flame. In doing so, that pre-mixed fuel and air is heated and then ignited.

If the boiler, or other device to be heated, requires more heat than the main pilot flame and the low fire flame can provide, the blower connected to the passageways 171 and 173 will be started and the valve that supplies gas to the pipe 190 will be opened. Pro-mixed fuel and air will then issue from the annular passage defined by the pipes 160 and 150, and supporting air will issue from the annular passage defined by the pipes 162 and 160. That pre-mixed fuel and air and that supporting air will establish a high fire flame for the combustion head. The pre-mixed fuel and air for the high fire flame will start inwardly along the path indicated by the dotted lines 272 in FIG. 2; and the inclination of that pre-mixed fuel and air and the velocity of the premixed fuel and 'air are such that the pre-mixed fuel and air will penetrate the main pilot flame. That main pilot flame will, at this time, be intimately'intermingled with thelow fire flame; and hence the pre-mixed fuel and air for the high fire flame will penetrate and be heated and ignited by the intermingled pilot and low fire flames. As a result, the .pre-mixed fuel and gas for the high fire flame will be ignited promptly.

The supporting air for the high fire flame will pass through the orifice defined by the baffle plate 168 and by the battle plate 166. That air will start inwardly along the path indicated by the dotted lines 274 of FIG. 2; and that air will-impinge upon and penetrate the main pilot flame, the low fire. flame, and the pro-mixed fuel and air for the high fire flame. The resultant interof the low fire flame and of the high fire flame is important and desirable because it provides a wildly turbulent intermixing of air and burning fuel which fosters rapid and complete combustion of the fuel.

spaced axially inwardly from the outlet end of the pipe 234, and it is spaced radially inwardly of the belled end of the pipe 234. As a result, that annular pilot flame turbulence and eddying of the flames to the right of the outlet end of pipe 234, and it is also protected from the air moving through the annular passage defined by the pipes 152 and 231). As a result, that annular pilot flame can be said to be substantially free of any likelihood of being accidentally extinguished.

.This is an important safety feature of the present inven- It will be noted that all of the angles which are subtended by the centerline of the combustion head and by the dotted lines 276, by that centerline. and by the dotted lines 272, and by that centerline and by the dotted lines 274 equal or exceeed sixty degrees. This is important in making sure that the various inwardly-directed fluids have the inclination needed to enable them to penetrate the flames upon which they impinge; which prevents stratification of the flames and which fully intermixes the fuel and air. It will also be noted that the angles subtended by the centerline of the comand it is that penetration 17 bustion head of FIG. 2 and the dotted lines 274 are greater than the angles subtended by that centerline and the dotted lines 272. This is important because the greater radial distance which the supporting air must traverse and the greater mass of flame which it must penetrate make the sharper angle necessary.

After the pro-mixed fuel and air for the low fire flame impinges upon and penetrates the main pilot flame, the intermingled main pilot and low fire flames will move to the right in FIG. 2 as a wildly turbulent, highly shredded, admixture of burning fuel, air, and products of combustion. When the premixed fuel and air and the supporting air therefor impinge upon and penetrate the intermingled pilot and low fire fiames, the entire area to the right of the bafiles 163, 166 and d in FIG. 2 becomes filled with a wildly turbulent, highly shredded, seething mass of burning fuel, air and products of combustion; and that mass is wholly free of Stratification. The temperature of that wildly turbulent, highly shredded, seething mass is so high that the fuel decomposes to hydrogen and carbon; and, consequently, the color of the overall flame is white and yellow rather than blue. The efiiciency of combustion provided by the combustion head of FIG. 2 is extremely high; and it makes it possible to reduce the amount of carbon monoxide in the products of combustion to levels approximately the theoretical minimums, and it makes it possible to do so with ruinimum excess air. The wildly turbulent, highly shredded, seething mass will move to the right in FIG. 2, and that mass will have a diameter exceeding the inner diameter of the baflie plate 168.

The temperature of the wildly turbulent, highly shredded, seething mass of burning fuel, air and product of combustion that issues from the combustion head of FIG. 2 is so high that a sleeve 280 of refractory material is telescoped within the outlet end of the pipe 162 to keep that outlet end from getting red hot. The inner end of that sleeve will abut the trailing face of the battle plate 168, and the outer end of that sleeve will extend beyond the outlet end of the pipe 162. In this way, the sleeve 280 will fully protect all of those portions of pipe 162 which would otherwise be exposed to the Wildly turbulent, highly shredded, seething mass of flame issuing from the combustion head of FIG. 2.

If, in the combustion head of FIG, 2, oil rather than gas is to be used as the fuel for the low fire and high fire flames, the oil spray nozzle 262 will be used to provide an intermittent oil spray that will lie between the dotted lines 266 of FIG. 2. The dual oil spray nozzles 264 will be used to provide intermittent oil sprays that will lie between the dotted lines 268.

The oil spray from the oil spray nozzle 262 will strike and penetrate the main pilot flame issuing from the pipe 23%; and as it does so it will be heated and ignited. The oil spray will rotate as it issues from the oil spray nozzle 262, and it will provide a turbulent flame that will intermingle with the main pilot flame. The supporting air for the low fire flame will issue from the annular passage between pipes 152 and 239.

The oil sprays from the dual oil nozzles 264 will strike and penetrate the intermingled main pilot and low fire flames; and as they do so they will be heated and ignited. The oil sprays from the dual oil nozzles 264 will rotate as they issue from the nozzles 264, and they will provide a turbulent flame that will intermingle with the main pilot flame and the low fire flame. The supporting air for the high fire flame will issue from the annular pasage between the pipes 162 and 168.

It will be noted that whether a gaseous fuel or a nongaseous fuel is used, both the low fire flame and the high fire flame are forced to strike and to penetrate the main pilot flame. Further, whether a gaseous or non-gaseous fuel is used, the high fire flame is forced to strike and penetrate the low fire flame. in these ways, full heat- T8 ing and ignition of all of the fuel is assured, and prompt and full combustion of the fuel is facilitated.

The refractory sleeve 280 that is telescoped within the outlet end of the pipe 162 of the combustion head of FIG. 2 has an opening 232 at the top thereof; and that opening is in register with a pipe 284 mounted on the exterior of the pipe 162. An opening is formed in the pipe 162 that is in register with the opening 282 in the refractory sleeve 289 and that is also in register with the interior of the pipe 284. The pipe 234 and the opening 282 permit a suitable monitoring device to monitor the main pilot flame of the combustion head of FIG. 2. The pipe 234- is mounted to the left of, but closely adjacent, the flange 285 at the outlet end of the pipe 162. That flange can be suitably secured to the exterior of a combustion chamber or combustion throat.

The numeral 2% denotes an orifice plate of refractory material. That orifice plate is square, and the length of each face thereof is equal to the outer diameter of the re fractory sleeve 28%. A circular orifice 288, is provided at the center of the orifice plate 286, and the leading edge of that orifice is smoothly rounded. The orifice plate abuts the right-hand end of the sleeve 286, and it will be suitably sealed to that end by cement.

A ported member 2%, that is square and that bounds an open area of square configuration, abuts the right-hand face of the orifice plate 286. That ported member has a number of ports 292 formed therein, and those ports extend at right angles to the outer faces of that ported memher.

A length 294 of square pipe of refractory material abuts the right-hand face of the square member 290, and that length of pipe is coaxial with the sleeve 280 and with the orifice 288. One or more additional lengths of square pipe of refractory material can be set in alinement with the length 294 of refractory pipe. The sleeve 280, the orifice plate 236, the ported member 290, and the lengths of pipe of refractory material constitute a combustion throat into which the burning fuel, air and products of combustion from the combustion head of FIG. 2 will be forced to pass.

Referring to FIGS. 6 and 7, the numeral 360 denotes an elongated combustion throat; and that combustion throat is circular in cross section, as shown by FIG. 7. A laterally-directed opening 301 is formed in one side of the combustion throat 3G0, and that opening permits the discharge through it of products of combustion. The numeral 302 denotes a vertically-directed wall that bounds one end of the opening 3M and that extends above and below the upper and lower edges of that opening. The numeral 383 denotes a vertically-directed wall that bounds the other end of the opening 301 and that extends above and below the upper and lower edges of that opening. The wall 303 also bounds one end of the combustion throat 300. The other end of the combustion throat is bounded by a wall 394. The combustion throat 300 and the walls 302, 303 and 3% are fabricated from suitable blocks or sections of refractory material; and those blocks or sections will be sealed together by a suitable cement.

The interior of the combustion throat 300 is provided with three axially extending grooves 305; and those grooves receive and support the corners of an inner combustion throat which includes the orifice plate 2S6, the ported member 2%, and the lengths 294 and 296 of pipe. Consequently, the orifice plate 286, the ported member 299, and the lengths 294 and 296 of pipe of the inner combustion throat receive full support from the outer combustion throat. As indicated by FIG. 7, the sections 294 and 2% of pipe are fabricated from fiat plates.

The numeral 306 denotes an opening in the wall 304, and that opening is shown on a larger scale in FIG. 8. A metal pipe 3628 is lodged within the outer end of the opening 3%, and the outer end of that pipe is threaded. A ring 310, which has inner and outer dimensions comparable to the inner and outer dimensions of the outer end of pipe 3&3, abuts the outer end of the pipe 363. A disc 312 of mica abuts the right-hand face of the ring 310; and a second ring 314, abuts the outer face of the mica disc 312. An annular cap 316 telescopes over the rings 31%) and 314 and over the mica disc 312 and is threaded onto the threaded outer end of the tube 3%.

An opening 329 is provided in the wall 3&3, and that opening receives and supports the'refractory sleeve 2%. A combustion head 322 will be connected to the sleeve 280; and that combustion head can be of the type disclosed in FIG. 1, can be of the type disclosed in FIG. 2, or can be of any other suitable type. The combustion head 322 will be pressurized;- and, where desired, it can be equippedwith a pipe 324 that has a valve 326 interidentical to the ring 310,

mediate the ends thereof. That pipe will extend from a pressurized air passage of the combustionhead 322 and will extend through an opening 327 in the wall 3% to supply air to the opening 301 of the combustion throat 300. That air is useful where the combustion apparatus is to be used to dehydrate products but is not intended to' burn those products. The air supplied by the pipe 324 and valve 326 will reduce the temperature of the.

products of combustion to levels at which the products beingdried will not be charred or burned. However, where the combustion throat 300 is to be used with a boiler, a furnace, or an oil cracking still, the pipe 324 and the valve 325 will not be needed.

As indicated particularly by FIG. 6 the pipe 368 in the opening 306 of wall 304 is aligned with the inner combustion throat, and it directly confronts the outlet end of the combustion head 322 which is secured to the in let of that inner combustion throat. This is important because the mica disc 312 is intended to serve as an explosion window; and explosions customarily exert their greatest forces along the axis of a burner. This means that if an explosion should occur in the combustion head 322, the force of that explosion would act directly and preponderantly upon the mica disc 312..

The mica disc 312 is dimensioned so it can withstand pressures up to ten inches of water gage but will break down when exposed to pressures in excess of ten inches of water gage. Since the pressures that are normally gen-' erated within the inner combustion throat and within the outer combustion throat do not exceed about three inches of water gage, themica disc 312 normally remains intact and prevents the escape of products of combustion. However, the pressures that are generated by even minor explosions exceed eight to ten pounds per square inch, and consequently the mica disc 312 will quickly break down and vent the products of combustion before the pressures within the combustion head and the combustion throats can build up to hurtful levels.

The mica disc 312 also serves as a window through which the burning process can be observed and inspected. The products of combustion will not reach and destroy the pipe 3% or the mica disc 312 because of the dead atmosphere that fills the opening 306 in the wall 364 of the combustion throat 3%. As a result, the present invention provides a long-lived disc which serves both as an explosion window and an inspection window.

The numeral 328 denotes the shell of a fire tube boiler. That shell has its inlet end disposed between the walls 392 and 303 which define the ends of the opening 3 391. A top wall 329 and a bottom wall 331 coact with the walls 362 and 303 to completely define the opening 303; and the walls 32? and 331 coact with the walls 302 and 303 to force the products of combustion and to move from the combustion throat 300 toward the inlet end of the boiler shell 328. Fire clay 330 is pressed solidly into position between the outer surface of the boiler shell 328 and the inner faces of the walls 302, 393, 329 and 331; and that fire clay will harden to a refractory-like consistency. In doing so, that clay will seal the combustion apparatus against the escape of products of combustion.

Channel-like beams 332 underlie the wall 331 and support that wall plus the combustion throat 3% and the inlet end of the boiler shell 328. Suitable supports and a suitable exhaust stack will be provided at the outlet end of the boiler shell 32-8.

In the operation of the combustion apparatus of FIGS. 6 and 7, burning fuel, air and products of combustion issue from the outlet end of the combustion head and enter the sleeve 28%. As the burning fuel, air and products of combustion approach the orifice 288 in the orifice plateZS-fi, they will be forced to converge, they will become denser, and they will move faster. As the burning fuel, air and'products of combustion pass through the orifice 238 and enter the ported member 2%, they will be permitted to diverge and to become less dense and to move slower. This divergence and this reduction in density and speed create a reduced pressure within the ported member 290.

The burning fuel, air and products of combustion will move through the pipe sections 2% and 2%; and, as they do so, more and more of the burning fuel and air are converted to products of combustion. The products of combustion, and any burning fuel and air intermingled therewith, will issue from the outlet end of the pipe 296 and will move toward the wall 364. As they approach, engage, and then rebound from the wall 3G4, the products of combustion and any intermingled burning fuel will heat that wall to a temperature at which that wall will be able to foster the burning of any further unconsumed fuel that leaves the pipe 296 and moves toward that wall. In actual practice, the wall 3% is heated to incandescence, and it greatly enhances the burning of any unconsumed fuel that engages it. As a result, any unconsumed fuel that reaches the wall 394 will be converted to products of combustion before it can leave the outer combustion throat 3%.

The combustion head 322 is disposed forwardly of and at one side of the boiler shell 328, and the wall 304 is disposed forwardly of and at the opposite side of that boiler shell. Hence, the burning fuel, air and products of combustion which issue from the combustion head 322 must move transversely of that boiler shell to reach the wall 3%. The distance between the outlet end of the combustion head 322 and the wall 3M is greater than the width of the'boiler shell 328; and, therefore, the burning fuel, air and products of combustion must traverse a distance, greater than the width of the boiler shell 323, before they can engage, and rebound from, the wall 364. This is very important because it gives the burning fuel time Within which it can largely be converted to products of combustion.

The combustion throat 30d coacts with the Wall 3% to dispose that wall at the inner end of a recess. The products of combustion and intermingled fuel will enter that recess as theymove toward the wall 304, and that recess will keep those products of combustion and intermingled fuel from turning and merely moving parallel to that face. Instead, that recess will force those products of combustion and intermingled fuel to move back toward the combustion head and toward the inner combustion throat. Asa result, the recess defined by the wall 3% and by the adjacent end of the combustion throat 3% fixedly controls the direction of movement of the gebfullding products of combustion and intermingled As the products of combustion, and any intermingled burning fuel, rebound from the wall 304, they will pass through further products of combustion and burning fuel from the pipe 2% and will cause violent turbulence. Al- :so, those rebounding products of combustion and any intermin led burning fuel will pass along the exterior surfaces of the top, bottom and sides of the pipe sections 294 and 2% and of the ported member 2%. Come quently, the rebounding products of combustion, and any intermingled burning fuel, will help assure full combustion of the further unconsumed fuel issuing from the pipe 296 and will help heat the sections 2%- and 296 and the ported member 299 to incandescence. The reduced pressure within the ported member 29% will draw a portion of the rebounding products of combustion in through the ports 292. Those inwardly-drawn products of combustion will heat and help ignite and burn the unconsumed fuel passing through the pipes 2% and 2%; and those inwardly-drawn products of combustion will also foster the ignition and burning of the fuel within the pipes 294 and 2% by striking the fuel and the products of combustion passing through the ported member 2% and causing turbulence.

From the foregoing, it should be apparent that the combustion throats of FIGS. 6 and 7 use the products of combustion and burning fuel that pass through them to enhance and to foster the rapid and complete burning of the fuel issuing from the combustion head 322. Specifically, the outer combustion throat uses the products of combustion and burning fuel to heat the wall Sti l to incandescence and thus enables that wall to foster the burning of any unconsumed fuel that engages it. Also, that outer combustion throat uses the products of combustion that rebound from the wall 304 to cause turbulence in further burning fuel and products of combustion issuing from the pipe 296. The inner combustion throat draws some of the rebounding products of combustion inwardly through the ports 292 to speed up the burning of fuel within the pipes 294 and 2%; .and that inner combustion throat also uses the rebounding products of combustion to heat that inner combustion throat to incandescence and thus enables that throat to foster the burning of any fuel passing through the pipes 294 and 296. In this way, the combustion throats of FIGS. 6 and 7 fully utilize the products of combustion before those products of combustion are permitted to pass to the boiler shell 328. Eurther, by providing the rebounding action, the resulting turbulence, the passage of the fuel through the incandescent inner throat, and the engagement of the fuel with the incandescent wall 3%, the combustion throats of FIGS. 6 and 7 assure full and complete conversion of all fuel to products of combustion before that fuel is permitted to leave the outer combustion throat 3%. This is very desirable, because it means that the products of combustion will be able to transfer the greatest part of their heat to the fire tubes of the boiler shell 32% without depositing any soot or lamp black in those tubes.

Referring to FIGS. 9 and 10, the numeral Mail denotes a combustion throat that is circular in cross section, as shown by FIG. 10. An opening 34?. is formed in one side of that throat, as shown by FIG. 10. One end of the opening 341 is bounded by a wall 342, and the other end of that opening is bounded by a wall 343. The wall 342 extends above and below the upper and lower edges of the opening 34-1; and it also constitutes a closure for one end of the combustion throat 34b. The wall 343 extends above and below the upper and lower edges of the opening 341, and it engages the combustion throat 349 adjacent the other end of that combustion throat. That other end of the combustion threat is closed by a wall 344.

The wall 342 has a cylindrical opening 382 therein, and that opening accommodates a cylindrical sleeve 333 of refractory material. One end of that sleeve is telescoped within the combustion head 322, and that combustion head can be of the type shown in FIG. 1, of the type shown in FIG. 2, or of any other suitable type. The other end of the sleeve 333 is disposed inwardly of the inner face of the wall 342. An orifice plate 334, which has a circular orifice 335, abuts the other end of the sleeve 333, and it will be suitably sealed to that other end of that sleeve by cement. The orifice plate 334- is rectangular in elevation, and that plate has its long axis vertical.

The bottom of that orifice plate is set in a recess at the bottom of the interior of the combustion throat 34b, and the orifice 335 in that plate is disposed below the level of, but in vertical registry with, the geometric axis of the combustion throat 3 2:9. An imperforate plate 336 of refractory material is mounted adjacent to, and in abutting relation with, the left-hand edge of the orifice plate 33 and a second imperf-orate plate 336 of refractory material is mounted adjacent to, and in abutting relation with, the right-hand edge of that orifice plate. The plates and 336 lie in the same plane and they are suitably sealed together by cement. The tops of the plates 336 are disposed below the level of the top of the plate 334, as shown by PEG. 10.

A ported member 352 of generally semi-elliptical configuration abuts the trailing faces of the plates 334 and 336. The ported member coacts with the bottom of the combustion throat 34b to define a generally elliptical space; and the long axes of the member 352 and of the space which it helps define are horizontally-directed. A number of ports 354 are formed in the ported member 352, and one of those ports is shown in FIG. 9. The leading face of the ported member 352 is suitably sealed to the trailing faces of the plates 33d and 336 by cement.

A number of arches 338 of refractory material are butted together to define a continuous arch that extends from the trailing face of the ported member 352 to a point adjacent the wall 343. Those arches are of generally semi-elliptical configuration, and they coact with the bottom of the combustion throat 346 to define a generally elliptical combustion throat which extends from the trailing face of ported member 352 to a point just short of the wall 344). Each arch 338 is made up of a number, preferably four, of blocks of refractory material; and those blocks are suitably sealed to each other and to the blocks of adjacent arches by cement. Angles 345 are embedded within the bottom of the combustion throat 3 th, and those angles underlie and provide full support for the bottom blocks of the various arches 338. A layer 356 of fire clay overlies and protects the right-hand portion of the angle 345 which is embedded in the combustion throat 340 a short distance below the lower edge of the opening 341.

The sleeve 333 corresponds to the sleeve 2% of FIG. 6, the ported member 352 corresponds to the ported memher 2% of PEG. 6, and the generally elliptical inner combustlon throat of FIGS. 9 and 10 corresponds to the square inner combustion throat of FIGS. 6 and 7. The principal advantage which the inner combustion throat of FIGS. 9 and it has over the inner combustion throat of FIGS 6 and 7 is its strength. The arches 338 have the curvature of a catenary, and hence they have the maximum possible resistance to sagging; and such resistance is vital in large installations. Because of that catenary configuration, the arches 338 of even very large installations will resist sagging even though those arches will be heated to incandescence.

A top wall 347 and a bottom wall 349 coact with the walls 342 and 343 to connect the opening 341 of combustion throat 34% with a fire tube boiler shell 346. Fire clay 343 is pressed into the space between the exterior of the boiler shell 34%: and the walls 342, 343, 347 and 349; and that clay will harden to a refractory-like consistency. In doing so, that clay prevents the escape and loss of products of combustion. Supporting beams 350 under lie the bottom Wall 349 and support that wall plus one end of the boiler shell 346.

An opening 306 is formed in the wall 344, and that opening is in alignment with the axis of the combustion head 322. A pipe 3% is mounted in the outer end of the opening 306, and a cap 316 is threaded onto the outer end of that pipe. The opening see, the pipe 368 and the cap 316 of FIG. 9 are identical to the correspondinglynumbered elements in FIG. 6; and hence the combustion throat 34b is provided with a readily frangible explosion and inspection window.

, fuel is to be used or where a In the combustion apparatus of FIGS. 9 and 10, as in the combustion apparatus of FEGS. 6 and 7, the burning fuel and products of combustion which issue from the combustion head are forced to converge and to become denser and to remove faster as they pass through the orifice of the orifice plate. As that fuel and those products of combustion diverge and become less dense and slow down, upon issuing through that orifice, they create a reduced pressure in the ported member. The burning fuel and the products of combustion then pass outwardly beyond the outlet end of the inner combustion throat and strike the refractory wall which confronts that outlet end. Thereupon,,tl1e burning fuel and products of combustion will rebound from the refractory wall and will move back toward the combustion head; and as they do so they mustpass through further oncoming burning fuel and products of combustion. The rebounding fuel and products of combustion will pass along the top of the inner combustion throat in a direction that is parallel to but is opposite the direction of movement which they had as they issued from the combustion throat. Some of the rebounding burning fuel and products of combustion will reach the ports 354 and will be drawn inwardly through those ports to help enhance the ignition and burning of fuel issuing from the combustion head 322.

In the combustion apparatus of FIGS. 6 and 7 and of FIGS. 9 and 10, the burning fuel and products of combustion heat the inner combustion throat and the far end wall of the outer combustion throat to incandescence, they foster the burning of the fuel by forcing that fuel to pass through the incandescent inner combustion throat and to engage and rebound from that incandescent wall and to pass along the exterior of that incandescent inner combustion throat, they also foster the burning of that fuel by forcing it to rebound through further oncoming burning fuel and products of combustion, and they additionally foster the burning of fuel by causing some of the products of combustion to be drawn back into the inner combustion throat to heat and ignite and to cause turbulence in further fuel from the combustion head.

F v In the combustion head of FIG. 2, the main pilot flame will preferably supply approximately one percent of the heating capacity, the low fire flame will preferably supply approximately four percent of that heating capacity, and the high fire flame will preferably supply the remaining ninety five percent of that heating capacity. Where this is done, the minimal needs of the boiler, or other device to be heated, will be met by the low fire flame and the maximal needs of that boiler or other heating device will be met by The baffles 166 and 156 of FIG. 2 will preferably be secured to the pipes 169 and 150, respectively, by screws or bolts. Where that is done, it will be an easy matter to replace those baffles with different battles where a dilferent different heating capacity is to be provided. Those different bafiies could have different frusto-conical configurations or different inner diameters, or both. Also, those bafiles could be mounted on extensions of the pipes 169 and 156 that would provide different advancements of those baffles relative to each other and relative to the other pipes of the combustion head of FIG. 2.

Whereas the drawings and accompanying description have shown and described several preferred embodiments of the present invention, it should be apparent to those skilled in the art that various changes can be made in the form of the invention without affecting the'scope thereof.

- What I claim is:

1. The combination of a heat-receiving means and a combustion apparatus that is adapted to supply heat to said means and that comprises a heat-receiving device, a pressurized combustion head, wall means that form a cornbustion throat which force products of combustion to move toward said device, means forming a refractory wall,

said combustion head being adapted to force burning fuel 7 ing products of and products of combustion toward said refractory wall, means including further walls which form a second combustion throat that guides and directs burning fuel and products of combustion from said combustion head to said refractory wall, said second combustion throat having an orifice plate intermediate the ends thereof with an orifice that forces the burning fuel and products of combustion to converge, to become denser and to move faster, said rifice plate having a trailing face, said combustion throat having a ported member adjacent the trailing face of said orifice plate that permits said burning fuel and products of combustion to diverge, to become less dense and to move slower and thereby create a reduced pressure Within said ported member, said second combustion throat having at least a portion of the exterior thereof exposed within the first sa'idcombustion throat, said second combustion throat extending toward but terminating short of said refractory wall to permit burning fuel and products of combustion that strike said refractory wall to rebound from said refractory wall and to pass along the. exterior of said second combustion throat, some of said reboundcombustion responding to reduced pressure within said ported member to enter said ported memher and to heat and cause turbulence in the burning fuel and products of combustion passing through said second combustion throat and thereby enhance the full combustion of said burning fuel.

2. The combination of a heat-receiving 'means and a combustion apparatus that is adapted to supply heat to said means and that comprises a heat-receiving device which has a front end and a back end, walls which form a combustion throat that is disposed forwardly of and that extends transversely of said device, said combustion throat being longer than said device is wide, a pressurized com: bustion head at one end of said combustion throat, a refractory wall at the opposite end of said combustion throat, and further. walls which form a second combustion throat that is disposed within and that is coaxial with the first said combustion throat, said second combustion throat being shorter than the first said combustion throat, said second combustion throat having at least a portion of the exterior thereof exposed within the first said combustion throat, said second combustion throat extending from said combustion head toward said refractory wall but terminating short of said refractory wall, said second combustion throat resting upon and being supported by the interior of the first said combustion throat, an opening in that wall of the first said combustion throat which is adjacent said device, said opening being spaced from said refractory wall, the first said combustion throat having an internal cross section that is circular, said second combustion throat having an external cross section that is non-circular to permit burning fuel and products of combustion to rebound from said refractory wall and to pass along the exterior of said second combustion throat, the first said combustion throat confining said rebounding burning fuel and products of combustion'and causing said rebounding burning fuel and products of combustion to move parallel to but oppositely of the direction in which they moved as they issued from said combustion head, the portions of the first said combustion throat adjacent said opposit end thereof defining a recess surrounding said refractory wall, said second combustion throat being longer than said device is wide whereby said second combustion throat confines and guides the burning fuel and products of combustion from said combustion head until said burning fuel and products of combustion have moved transversely of said front end of said device, said second combustion throat having an orifice plate intermediate the ends thereof with an orifice that forces the burning fuel and products of Combustion to converge, to become denser and to move faster, said orifice plate having a trailing face, said second combustion throat having a ported member adjacent the trailing face of said orifice plate that permits said burning fuel and products of combustion to diverge, to

become less dense and to move slower and thereby create a reduced pressure within said ported member, some of said rebounding products of combustion responding to reduced pressure within said ported member to enter said ported member and to heat and cause turubulence in the burning fuel and products of combustion passing through said second combustion throat, said second combustion throat and said refractory wall being adapted to become in candescent and to foster the burning of fuel issuing from said combustion head.

3. The combination of a heat-receiving means and a combustion apparatus that is adapted to supply heat to said means and that comprises a heat-receiving device which has a front end and a back end, walls which form a combustion throat that is disposed forwardly of and that extends transversely of said device, said combustion throat being longer than said device is wide, a pressurized combustion head at one end of said combustion throat, a refractory wall at the opposite end of said combustion throat, and further walls which form a second combustion throat that is disposed within and that is coaxial with the first said combustion throat, said second combustion throat being shorter than the first said combustion throat, said second combustion throat having at least a portion of the exterior thereof exposed within the first said combustion throat, said second combustion throat extending from said combustion head toward said refractory wall but terminating short of said refractory wall, said second com bustion throat resting upon and being supported by the interior of the first said combustion throat, an opening in that wall of the first said combustion throat which is adjacent said device, said opening being spaced from said refractory wall, the first said combustion throat having an internal cross section larger than the external cross section of said second combustion throat to permit burning fuel and products of combustion to rebound from said refractory wall and to pass along the exterior of said second combustion throat, the portions of the first said combustion throat adjacent said opposite end thereof defining a recess surrounding said refractory wall, said second combustion throat being longer than said device is wide whereby said second combustion throat confines and guides the burning fuel and products of combustion from said combustion head until said burning fuel and products of combustion have moved transversely of said front end of said device, said second combustion throat having an orifice plate intermediate the ends thereof with an orifice that forces the burning fuel and products of combustion to converge, to become denser and to move faster, said orifice plate having a trailing face, said second combustion throat having a ported member adjacent the trailing face of said orifice plate that permits said burning fuel and products of combustion to diverge, to become less dense and to move slower and thereby create a reduced pressure within said ported member, some of said rebounding products of combustion responding to reduced pressure within said ported member to enter said ported member and to heat and cause turbulence in the burning fuel and products of combustion passing through said second combustion throat.

4. The combination of a heat-receiving means and a combustion apparatus that is adapted to supply heat to said means and that comprises a heat-receiving device which has a front end and a back end, walls which form a combustion throat that is disposed forwardly of and that extends transversely of said device, a pressurized combustion head at one end of said combustion throat, a refractory wall at the opposite end of said combustion throat, and further walls which form a second combustion throat that is disposed within the first said combustion throat, said second combustion throat confining and guiding the burning fuel and products of combustion from said combustion head and directing said burning fuel and products of combustion toward said refractory wall, said refractory wall coacting with the pressurization of said combustion head to cause said burning fuel and products of combustion to rebound toward said second combustion throat and toward said combustion head, said second combustion throat having an orifice plate intermediate the ends thereof with an orifice that forces the burning fuel and products of combustion to converge, to become denser and to move faster, said orifice plate having a trailing face, said second combustion throat having a ported member adjacent the trailing face of said orifice plate that permits said burning fuel and products of combustion to diverge, to become less dense and to move slower and thereby create a reduced pressure within said ported member, some of said rebounding products of combustion responding to reduced pressure within said ported member to enter said ported member and to heat and cause turbulence in the burning fuel and products of combustion passing through said second combustion throat.

5. The combination of a heat-receiving means and a combustion apparatus that is adapted to supply heat to said means and that comprises a heat-receiving device which has a front end and a back end, walls which form a combustion throat that is disposed forwardly of and that extends transversely of said device, a pressurized combustion head at one end of said combustion throat, a refractory wall at the opposite end of said combustion throat, and further walls which form a second combustion throat that is disposed within the first said combustion throat, said second combustion throat having at least a portion of the exterior thereof exposed within the first said combustion throat, said second combustion throat confining and guiding the burning fuel and products of combustion from said combustion head and directing said burning fuel and products of combustion toward said refractory wall, said refractory wall coacting with the pressurization of said combustion head to cause said burning fuel and products of combustion to rebound toward said second combustion throat and toward said combustion head, said second combustion throat having an orifice plate intermediate the ends thereof with an orifice that forces the burning fuel and products of combustion to converge, to become denser and to move faster, said orifice plate having a trailing face, said second combustion throat having a ported member adjacent the trailing face of said orifice plate that permits said burning fuel and products of combustion to diverge, to become less dense and to move slower and thereby create a reduced pressure within said ported member, some of said rebounding products of combustion responding to reduced pressure within said ported member to enter said ported member and to heat and cause turbulence in the burning fuel and products of combustion passing through said second combustion threat.

6. In combustion apparatus, for products that are to be heated without being charred or burned, that has a combustion head which is pressurized, walls which form a combustion area adjacent said combustion head, said pressurized combustion head forcing fuel into said combustion area under pressure and also forcing into said combustion area under pressure substantially all of the air used to burn that fuel, whereby said pressurized combustion head will establish and maintain a super-atmospheric pressure within said combustion area, pipe means extending from said pressurized combustion head to said combustion area, said pressurized combustion head being adapted to provide a flow of air through said pipe, and valve means that controls said flow of air through said pipe means, said valve means and said pipe means being adapted to conduct air from said pressurized combustion head to said combustion area to cool the temperature of the products of combustion in said combustion area below the level at which said products of combustion can char or burn said products to be heated.

7. The combustion of a heat receiving means and a combustion apparatus, that is adapted to supply heat to said means, that comprises a heat-receiving device which has an inlet end and an outlet end and which absorbs heat eneaeoe 37 from products of combustion that enter said inlet end and that pass to said outlet end, a pressurized combustion head that is disposed forwardly of and at one side of said inlet end of said device, means including walls that forms a combustion throat which receive products of combustion from said pressurized combustion head and which guide said products of combustion as they move along a path leading to said inlet end of said device, said pressurized combustion head forcing fuel into said combustion throat under pressure and also forcing into said combustion throat under pressure substantially all of the air used to burn that fuel, whereby said pressurized combustion head will establish'and maintain a super-atmospheric pressure within said combustion throat, and means including a refractory wall that is disposed forwardly of and at the opposite side of said inlet end of said device, said combustion head and said combustion throat. being adapted to force burning fuel and products of combustion toward said refractory wall and said refractory wall being adapted to cause said burning fuel and products of combustion to rebound toward said combustion head, said combustion head and said refractory Wall being spaced apart a distance greater than the Width of said device and said refractory wall being part of a recess extending outwardly beyond said opposite side of said device, said-recess having generally cylindrical Walls adjacent the inlet thereof, said combustion throat having the outlet end thereof projecting into said inlet of said recess so burning fuel and products of combustion from said combustion head must enter said recess and must engage and rebound from said refractory wall, said inlet of said recess and said outlet end of said combustion throat coacting to define a restricted opening in communication with the inletend of said heat-receiving device, said recess confining the burning fuel and products of combustion that rebound from said refractory wall and that move toward said restricted opening, said refractory wall being adapted to become incandescent and to foster the burning of fuel issuing from said combustion throat, the burning fuel and products of combustion which rebound from said refractory wall and then pass to and through said restricted opening passing through and causing turbulence in further burning fuel and products of combustion issuing from said combustion throat, said re- ;fractory wall causing burning fuel and products of combustion from said combustion throat to rebound toward said combustion head and coacting with said combustion throat and said recess to cause substantially all of the burning fuel and products of combustion issuing from said combustion head to move transversely of said device, to engage said refractory wall, to reverse direction and again move transversely of said device but in the opposite direction, and to pass through said restricted opening before turning and moving toward said device, said products of combustion subsequently responding to the continued forcing of fuel and air under pressure into said combustion throat and to the conversion of said fuel to products of combustion to pass to and enter said inlet of said device.

8. The combination of a heat-receiving means and a combustion apparatus, that is adapted to supply heat to said means, that comprises a heat-receivingdevice which has an inlet end and an outlet end and whichabsorbs heat from products of combustion that enter said inlet end and that pass to said outlet'end, a pressurize combustion head that is disposed forwardly of and at one side of said inlet end of said device, including walls that form a combustion throat Which receive products of combustion from said pressurized combustion head and which guide said products of combustion as they move along a path leading to said inlet end of said device, means including a refractory wall that is disposed forwardly of and at the opposite side of said inlet end of said device, and means including further walls which form a second combustion throat that guides and directs burning fuel and products of combustion from said combustion head to said refractory wall, said refractory wall, said refractory wall being within a end of said combustion throat, said combustion throat under recess which has generally cylindrically walls adjacent the inlet thereof, said second combustion throat having the ing toward but terminating short of said refractory wall to permit burning fuel and products of combustion that strike said refractory wall to rebound'from said refractory wall and pass throughsaid restricted opening and to pass along the exterior of said second combustionthroat, said second combustion throat having at least a portion of the exterior thereof exposed Within the first said combus tion throat, said second combustion throat confining burning fuel from said pressurized combustion head and forcing said burning fuel and products of combustion to pass into said recess and to engage and rebound from said refractory wall, said cylindrical walls adjacent said inlet of said recess forcing the burning fuel and products of coinbustion thatrebound from said refractory wall to move back toward said second combustion throat and to pass through said'restricted opening in a direction generally parallel to the axis ofsaid second combustion throat, said second combustion throat beingdirected transversely of said device, the burning fuel and products of combustion that rebound from said refractory Wall and that pass outwardly through said restricted opening passing through and causing turbulence in further burning fuel and products of combustion issuing from said secondcom-bustion throat, said second combustion throat forcing substan: tially all of the fuel and products of combustion issuing from said combustion head to strike said refractory wall, said products of combustion subsequently responding to the continued forcing of fuel and air under pressure into said combustion throat and to the conversion of said fuel to products of combustion to pass to and enter said inlet end ofsaid device.

, 9. The combination of a heat-receiving means and a combustion apparatus, that is adapted to supply heat to said means, that comprises a heat-receiving device which has a front end and a back end, walls which form a combustion throat that is disposed forwardly of and thatextends transversely ofsaid front end of said device, a'pressurized combustion head at one end of said combustion throat, means including a refractory'wall at the opposite walls which form said combustion throat also forming a recess adjacentsaid refractory wall, and further means including walls which form a second combustion throat that is disposed within and that is coaxial with the first said combustion throat, said second combustion throat being shorter than the first said combustion throat, said second combustion throat having at least a portion of the exterior thereof exposed within the first said combustion throat, said second combustion throat extending from said combustion head toward said refractory wall but terminating short of said refractory wall and terminating immediately adjacent the inlet of said recess, the outlet end of said second combustion'throat coacting with said inlet of said recess to define a restricted opening intermediate said combustion head and said refractory wall, in communication with the inlet end of said heat-receiving device, said pressurized combustion headforcing fuel-into said second combustion throat under pressure and also forcing into said second pressure substantially all of the air used to burn that fuel, whereby said pressurized cornbustion head will establish and maintain a superatmospheric pressure within said second combustion throat, said second combustion throat resting upon and being supported by the interior of the first said combustion throat, an opening intha't Wall of the first said combustion throat which is adjacent said device, said opening being spaced from said refractory wall by at least the depth of said recess, the first said combustion throat having an internal cross section larger than the external cross section of said second combustion throat to 

1. THE COMBINATION OF A HEAT-RECEIVING MEANS AND A COMBUSTION APPARATUS THAT IS ADAPTED TO SUPPLY HEAT TO SAID MEANS AND THAT COMPRISES A HEAT-RECEIVING DEVICE, A PRESSURIZED COMBUSTION HEAD, WALL MEANS THAT FORM A COMBUSTION THROAT WHICH FORCE PRODUCTS OF COMBUSTION TO MOVE TOWARD SAID DEVICE, MEANS FORMING A REFRACTORY WALL, SAID COMBUSTION HEAD BEING ADAPTED TO FORCE BURNING FUEL AND PRODUCTS OF COMBUSTION TOWARD SAID REFRACTORY WALL, MEANS INCLUDING FURTHER WALLS WHICH FORM A SECOND COMBUSTION THROAT THAT GUIDES AND DIRECTS BURNING FUEL AND PRODUCTS OF COMBUSTION DEOM SAID COMBUSTION HEAD TO SAID REFRACTORY WALL, SAID SECOND COMBUSTION THROAT HAVING AN ORIFICE PLATE INTERMEDIATE THE ENDS THEREOF WITH AN ORIFICE THAT FORCES THE BURNING FUEL AND PRODUCTS OF COMBUSTION TO CONVERGE, TO BECOME DENSER AND TO MOVE FASTER, SAID ORIFICE PLATE HAVING A TRAILING FACE, SAID COMBUSTION THROAT HAVING A PORTED MEMBER ADJACENT THE TRAILING FACE OF SAID ORIFICE PLATE THAT PERMITS AID BURNING FUEL AND PROTECTS OF COMBUSTION TO DIVERGE, TO BECOME LESS DENSE AND TO MOVE SLOWER AND THEREBY CREATE A REDUCED PRESSURE WITHIN SAID PORTED MEMBER, SAID SECOND COMBUSTION THROAT HAVING AT LEAST A PORTION OF THE EXTERIOR THEREOF EXPOSED WITHIN THE FIRST SAID COMBUSTION THROAT, SAID SECOND COMBUSTION THROAT EXTENDING TOWARD BUT TERMINATING SHORT OF SAID REFRACTORY WALL TO PERMIT BURNING FUEL AND PRODUCTS OF COMBUSTION THAT STRIKE SAID REFRACTORY WALL TO REBOUND FROM SAID REFRACTORY WALL AND TO PASS ALONG THE EXTERIOR OF SAID SECOND COMBUSTION THROAT, SOME OF SAID REBOUNDING PRODUCTS OF COMBUSTION RESPONDING TO REDUCED PRESSURE WITHIN SAID PORTED MEMBER TO ENTER SAID PORTED MEMBER AND TO HEAT AND CAUSE TURBULENCE IN THE BURNING FUEL AND PRODUCTS OF COMBUSTION PASSING THROUGH SAID SECOND COMBUSTION THROAT AND THEREBY ENHANCE THE FULL COMBUSTION OF SAID BURNING FUEL. 